ŚVETĀŚVATARA UPANISHAD · 3.12
महान् प्रभुर् वै पुरुषः सत्त्वस्यैष प्रवर्तकः ।
सुनिर्मलाम् इमां प्राप्तिम् ईशानो ज्योतिर् अव्ययः ॥
mahān prabhur vai puruṣaḥ sattvasyaiṣa pravartakaḥ ।
sunirmalām imāṃ prāptim īśāno jyotir avyayaḥ ॥
That person (purusha) is the great lord; he is the mover of existence, he possesses that purest power of reaching everything, he is light, he is undecaying.
F. Max Müller · The Upanishads, Sacred Books of the East 15 (1884)